1. Field of the Invention
The present invention relates to an image processing apparatus, and an image processing method for performing image processing corresponding to printing, and a storage medium storing a program.
2. Description of the Related Art
In recent years, color printers capable of printing monochrome images have become widely known due to the arrival of ink jet printers that include multicolor ink such as grey ink. Generally, with a color printer, when a color image is developed into color material colors, color material color development processing is performed by referencing a three-dimensional lookup table (3DLUT). U.S. Pat. No. 6,459,501 discloses a method of processing monochrome image data using a nearly achromatic color reproduction region (small gamut), which is a restricted gamut.
Generally, a monochrome image requires tone to be expressed more finely compared to a color image. Because of this, a greater degree of tone reproduction control is needed for monochrome image data than for color image data. In view of this, with color material color development processing by a printer capable of printing a monochrome image, it is necessary to implement, in the 3DLUT, more grid points than the number of grid points needed for color image processing.
In U.S. Pat. No. 6,459,501, image quality is improved by using a small gamut obtained by restricting the gamut, but since the number of grid points is the same as in color image processing, the performance of tone reproduction control is also the same as in color image processing. Also, it is conceivable for monochrome image processing that implements a larger number of grid points to be configured separately from color image processing. However, the provision of a hardware configuration separate from that of color image processing causes an increase in circuit size. Also, in color image processing, it is conceivable for a larger number of grid points to be implemented to match the image quality of monochrome image data with a high level of tone reproduction control. However, an increase in the number of grid points in the 3DLUT will end up causing an increase in circuit size. Also, the amount of memory increases as well with respect to processing performed by software, and therefore the efficiency of printing processing decreases.